JP2006509927A - Yarn processing device control method - Google Patents

Abstract

A method for starting or stopping each of at least two separately controllable roll sets (22, 26, 34, 56) used to treat a yarn (Y) in a stretch-break process, Each roll set comprises at least two rolls, and the method follows a predetermined sequence and minimizes the simultaneous complete failure of the yarn (Y) being processed in the stretch-break process A method characterized by the process of each roll set that changes the speed of each roll from an initial condition to a steady state condition in coordination with a change in at least one speed of the roll.

Description

  The present invention relates to control of yarn processing equipment in a stretch-break process, and more particularly to a method for initiating a process in a coordinated manner.

  The textile industry utilizes commercial multi-position spinning machines that can wind multiple spindles of the same product. One type of commercial yarn making machine, known as a ring spinning machine, produces staple yarns directly. The manufacturing throughput of such machines is relatively limited.

  Another direct spinning apparatus, referred to as a “stretch-break” apparatus for the purposes of this application, improves throughput by producing staple yarns directly from multifilament yarn feed in a continuous operation. A schematic diagram of the functional and enabling elements at one location 12A of the stretch-break device, generally represented by reference numeral 10, is shown in the box drawn at point in FIG. One or more additional stretch-break locations 12B, 12C, ... 12N, each identical to location 12A, may be provided to define multi-position device 10. The device 10 is disclosed and claimed in a co-pending application (Patent Document 2) published internationally on December 21, 2000 as (Patent Document 1).

  It should be understood that throughout the following description of the stretch-break apparatus, each roll at one location may be implemented as multiple rolls with or without associated nip rolls. It should also be understood that the pressure applied by the nip roll may be controlled manually or by an associated control device.

  Position 12A includes a draw and anneal zone 20, a first break zone 30, a second break zone 40 (as a rebreak zone) connected in series between the continuous source 16 of yarn Y and the winding zone 60. Also includes an enhancement zone 50.

  The yarn source 16 may include a dispenser 18 driven by an enabling dispense controller 19 as shown, or another suitable yarn supply device. The feeding control device 19 may be realized by a braking mechanism or a feeding motor so as to control the tension of the yarn Y supplied from the feeding machine 18.

  The stretching and annealing zone 20 is defined between a roll 22 and a driven roll 26 and includes a hot plate 24. Roll 22 includes enabling heater 22H and hot plate 24 includes enabling heating element 24H. The roll 26 may also include an enabling heater 26H. As is well known, the driven roll 26 must rotate at a higher surface speed than the surface speed of the heated roll 22 in order to provide a stretching action. The ratio of the surface speed of the roll 26 to the surface speed of the roll 22 is called the “stretch ratio”.

  The first break zone 30 is defined between the roll 26 and the roll 34, and the second break zone 40 is defined between the roll 34 and the roll 42. The ratio of the surface speed of the roll 34 to the surface speed of the roll 26 is called the “stretch-break ratio”, and the ratio of the surface speed of the roll 42 to the surface speed of the roll 34 is called the “re-break ratio”. An optional jet 32 with an enabling air source 32S may be included in the first break zone 30. The second break zone 40 may include an optional jet 36 with an associated enabling air source 36S.

  The reinforcement zone 50 is defined between roll 42 and roll 56 and may include one or more reinforcement jets 52 and their enabling air supply 52S. The reinforcing device may also be a mechanical or other fluidic device designed to strengthen the yarn Y. The ratio of the surface speed of the roll 56 to the surface speed of the roll 42 is called the “strengthening ratio”.

  The winding zone 60 includes a traverse winder 62 for collecting the finished staple yarn S on the bobbin B. The winder 62 has associated enabling winders and traverse drives 62D, 62T. A waste jet 58 and its enabling air source 58S may immediately precede the winder 62 to facilitate stringing. The ratio of the surface speed of the winder 62 to the surface speed of the roll 56 is called “winding tension” (table of FIG. 4).

  Individual rolls that are in sequential contact with the yarn Y during the stretch-break process may be paired into an operational roll set. Accordingly, the rolls 26 and 34 may define the first roll set 30S, the rolls 34 and 42 may define the second roll set 40S, and the rolls 42 and 56 may be the third roll. The set 50S may be defined. Each roll 22, 26, 34, 42, and 56 has an associated enabling drive motor 23, 27, 35, 43, and 57, respectively.

  Alternatively, as seen in FIG. 1A, the roll 34 may be functionally realized by a number of rolls, such as dual rolls 34A, 34B. Similarly, the roll 42 may be functionally realized by a number of rolls such as dual rolls 42A, 42B. In such an alternative configuration, rolls 26, 34A, rolls 34B, 42A, and rolls 42B, 56 may define operational roll sets 30S ', 40S', 50S ', respectively. Rolls 34A, 34B, 42A, and 42B have associated drive motors 35A, 35B, 43A, and 43B, respectively.

  During operation, a yarn Y composed of filaments F is introduced into the drawing and annealing zone 20. Within the drawing and annealing zone 20, the yarn Y is heated to the annealing temperature by the combination of the heater 22 </ b> H in the heated roll 22 and the hot plate 24. The first roll 22 in the draw and anneal zone 20 grips the incoming filament F, and the second roll (ie roll 26) of the operating roll set draws and stretches them. The surface speed of the roll 26 may be set relative to the surface speed of the roll 22 to stretch the heated yarn Y, if necessary, to obtain the desired tensile properties.

  The annealed yarn Y proceeds to the first break zone 30. During steady state operation, the first roll 26 in the break zone 30 grips the annealed filament and the second roll of the operating roll set, ie, optionally roll 34 (FIG. 1) or roll 34A (FIG. 1A) stretch-stretches them until all of the filaments F break randomly. The filament F may be further broken at a second break zone 40 disposed downstream from the first break zone 30. An optional jet 36 may be used to control the end of the filament broken in the first break zone to prevent roll wrapping.

  Next, the yarn Y is reinforced in the reinforced zone 50 to form the staple yarn S. Staple yarn S is wound onto bobbin B by winder 62 under controlled tension and traverse speed.

  The stretch-break process as implemented in apparatus 10 is particularly difficult to start because the dynamic stretch and break properties of the yarn differ at different speeds and differ from its static properties. The goal of the stretch-break process is to randomly break all of the filaments in both time and position. In the apparatus of FIG. 1, all filaments are randomly broken in a first stretch-break zone 30, and those broken filaments are randomly rebroken in a second rebreak zone 40. Aggressive initiation may result in simultaneous complete failure of all filaments in any zone, resulting in loss of yarn string-up through the device and generation of waste products.

  Startup is particularly complicated by the interaction of process parameters. For example, yarn stretch-break resistance (ie, failure of some filaments without full failure) is affected by the annealing temperature, which varies throughout startup. Yarn stretch-break resistance also changes significantly as the roll speed changes, and the relative speed ratio of the rolls in a given roll set changes throughout the start-up. Jet parameters, particularly operating pressure, affect the degree of fiber entanglement, and winding parameters such as winding tension also affect yarn stretch-break resistance.

International Publication No.0077283 Pamphlet US patent application Ser. No. 09 / 979,808

  In view of the above, it would be beneficial to provide a computer-implemented method for controlling the transition from initial to steady state conditions of a single-position or multi-position stretch-break process that minimizes the possibility of complete yarn breakage and disposal It is thought that. It would be further advantageous to be able to control the process parameters according to a predetermined “recipe” tailored to each individual yarn. As used herein, the term “recipe” is a predetermined sequence of changes in operating parameters for various enabling elements at each location of the stretch-break device. For example, a given recipe may have a change in speed of at least one other roll (ie, the ratio of the speed of a given roll set), the temperature of each heater or heated roll, the associated jet operating parameters (ie , Pressure state), and winder tension, in turn, specify a sequential change in the speed of each roll, causing the processing position to stop or transition from an initial condition to a steady state operating condition. The parameter transition may be changed stepwise or continuously.

  The present invention comprises a computer-implemented method and program for initiating each of at least three separately controllable roll sets used to process a yarn Y in a stretch-break process. Each roll set comprises at least two rolls. In the method of the present invention, for each roll set, in accordance with a predetermined sequence and in coordination with at least one speed change of the other roll, so as to minimize complete breakage of the yarn Y being processed in the stretch-break process. Then, the speed of each roll is changed from the initial condition to the steady state condition.

  The startup sequence of this method may be implemented in two ways. In the first aspect, the speed of each roll is varied in at least two separate steps to achieve a steady state set of roll speeds. In the second aspect, the speed of each roll is continuously changed to a steady state roll speed.

The predetermined sequence is
a) selecting a candidate speed for each roll;
b) confirming the validity of the candidate speed for each roll against a predetermined operability standard;
c) For a speed that satisfies the operability criteria, a speed is set for each roll.

  The invention will be more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, which form a part of this application.

  Throughout the following detailed description, like reference numerals refer to like elements in all figures of the drawings.

  FIG. 2 shows a control comprising a computer 112 and an associated controller 118 for executing a program according to the method of the present invention to control each position 12A to 12N of the multi-position stretch-break device 10 according to a predetermined recipe. 2 is a detailed block diagram of system 110. FIG. The control system 110 may be implemented using a standard desktop personal computer 112 and one or more commercially available programmable logic controllers (PLCs) 118.

  The computer 112 is connected by a data and control bus 122 to a central processing unit (CPU) 124, memory 126, operator display 128, keyboard 142 and mouse 144 for operator input, input-output interface 130 and associated storage devices. 116. Memory 126 may be implemented as random access memory (RAM) or another suitable memory device, and may be partitioned into memory units 152A, 152B,. Operator display 128 includes a cathode ray tube (CRT), a liquid crystal display (LCD), or some other device for displaying a graphical user interface 114 that an operator communicates with computer 112 using keyboard 142 and mouse 144. . The visual graphic generated by the graphical user interface 114 for one location is shown in FIG.

  A suitable cable assembly 120 implements a bus network for connecting the computer 112 with each controller 118 using any standard bus protocol. Each controller 118 comprises a central control unit 118C and associated input-output (I / O) interfaces 118-1, 118-2, 118-3, 118-4, 118-5. Each I / O interface is connected to the control devices 210-250 by the cable assembly 200 one after the other. Each control device 210-250 is associated with a respective enabling element for one location 12A-12N.

  As shown, the I / O interface 118-1 is connected to a motor inverter unit 210 that is connected to the drive motors 23, 27, 35, 43, and 57 one after another. The I / O interface 118-2 is connected to the heater control 220, which in turn is connected to the heaters 22H and 24. I / O interface 118-3 is connected to jet control 230, which in turn is connected to jets 32, 36, 52, 54, and 58. The I / O interface 118-4 is connected to the yarn supply tension control 240, which in turn is connected to the payout controller 19. The I / O interface 118-5 is connected to a winder control 250, which in turn is connected to a winder drive 62D and a winder traverse 62T. It should be understood that a multi-channel PLC may be used that can interface various enabling elements for two or more locations 12A-12N of the device 10.

  Having described the physical elements and control system architecture, a book that allows each location 12A-12N to be operated independently using individual and completely different process recipes downloaded to the controller 118. The operation of the inventive method may now be described.

  The present invention stores a command for realizing a process recipe in the computer memory 126. When these commands are executed, the control system 110 causes the position to perform a multi-step sequence or a continuous sequence.

  A table of predefined operability criteria (ie, operational limits) for various parameters is stored in computer memory. An example of operability criteria is the maximum allowable stretch ratio at a given temperature for a particular type of yarn Y. The predetermined operability criteria will provide an operability limit for a given yarn product that allows the roll set speed and resulting roll speed ratio to be incrementally varied to achieve the desired steady state operating conditions. It may be determined experimentally.

  Recipes for a given yarn product can be developed by the operator. Various candidate parameters for each operating condition are selected. Each candidate parameter is validated against its associated predetermined usability criteria. If the candidate parameter meets the operability criteria, the parameter is input to the recipe. If the candidate parameter does not satisfy the operability condition, the candidate parameter is denied entry to the recipe. The completed recipes shown as memory segments 154A-154F may be stored using conventional computer file storage techniques.

  Process recipe programming flexibility is important because yarns made from different filaments (ie, different deniers or different materials) may have completely different physical characteristics. Each yarn type or combination of yarn types operates differently in the draw and anneal zone, break zone, rebreak zone, strengthen zone, and take-up zone (20-60 in FIG. 1). In a multi-step recipe, each step in the recipe incrementally changes parameters in one of more zones. Each incremental step cooperates to change the roll speed ratio until the operating speed is achieved. Similarly, a continuous recipe will gradually increase and change the roll speed ratio continuously until the operating speed is achieved (this may be approximated by incrementing the speed in many very small steps). ).

  The method of the present invention may be implemented by using system control device 110 to download recipes from desktop computer 112 to controller 118 associated with a given location. The system control device facilitates multiple multi-step process recipes or continuously changing process recipes to be written, modified and stored. The operator selects from a predetermined multi-step process recipe stored in memory 126 (or storage device 116) and any one control associated with a yarn processing position (such as 12A) or a group of positions (such as 12A-12C). The selected recipe can be downloaded to the device 118. This download process is the transfer of recipe data from the system computer 112 to a dedicated position programmable logic controller (PLC) 118, thus freeing the computer 112 for other tasks.

  Next, the PLC 118 controls the drive motors 23, 27, 35, 43, 57, the associated motor inverter unit 210, the heater control 220 for controlling the heaters 22H and 24H, and the jets 32, 36, 52, 54. , And 58, a yarn feed tension control 240 for controlling the feed control device 19, and a winder control 250 for controlling the winder drive 62D and the traverse drive 62T.

  Once the data is distributed to the selected control device (210-250) associated with a particular location, that location (such as 12A) is independent of the system control device 110 and other ambient locations. It can operate independently (such as 12B or 12C). Since each location 12A-12N can potentially operate with a different multi-step process recipe, a separate local read / operator interface 214A-214N (FIG. 1) is available for each location 12A-12N. Provided to. This local readout 214 allows the operator to control the position and monitor all of the unique position specific data as well as display position and system fault messages.

  Note that the recipe is not specific to motor speed alone. The recipe also includes operating parameters such as stretching and annealing zone heater temperatures, and pressure settings for aspirators, reinforced jets, and nip rolls (not shown). The recipe may also include winder specific parameters such as twist angle, traverse length, package pressure, and package length or diameter. Automatic process string up may also be accommodated in the recipe. This can be done by providing a specified time for each process to operate before proceeding automatically to the next sequential process.

  A new recipe can be developed using the graphical display generated by the user interface 114 shown in FIG. The graphical display has a window associated with various icons that graphically represent the hardware elements. Each window represents operating parameters of the enabling element for a particular process in the recipe. As can be understood by looking at the list in the upper left corner of the display, up to 10 recipes may be accommodated. If the candidate parameter meets the operability criteria, the parameter is entered into a new recipe. If the candidate parameter does not meet operability criteria, the operator is alerted (such as by a color change or flashing warning) and the candidate parameter is denied entry into the recipe.

  The multi-step process recipe shown as steps 1 to 6 in the top row of the table is tabulated in FIG. The operating parameters are identified in the left column of the table. Each step of the recipe can be created or modified by use of the graphical interface 114. FIG. 3 shows operation parameters corresponding to step 6 of the recipe of FIG. The calculated roll speed is displayed based on the recipe and process specific ratio. The roll speed of the next process is coordinated with the previous roll speed by multiplying the previous roll speed by the process specific ratio. Thus, by entering the initial or final roll speed and all zone ratios, all other related roll speeds can be calculated using the reference roll set selection routine.

The reference roll set selection routine allows roll set speed calculations to be initiated forward from roll 1 (heated roll 22 in FIG. 1) or backward from roll 5 (roll set 56 in FIG. 1). To do. This allows the operator to design a process specific recipe by specifying several parameters as follows.
1) Specify the required start speed and calculate other speed, or specify the required end speed and calculate other speed,
2) Specify the final yarn package diameter or package length that may be entered (if a value is entered in both, the first to be achieved during the operation is the operating parameter that results in a package doff become),
3) Specify acceleration and deceleration times in seconds, which refer to process specific times for the motor to accelerate or decelerate to the next or previous process speed, respectively. The following calculation is necessary to determine the motor frequency acceleration.

The accuracy of this calculation must be at least 0.1% (ie, 10 ⁻³ ) because all rolls must achieve their final speed accurately to maintain the desired ratio. Because it must. This gradual progression of the process ratios of draw and anneal zone, break zone, rebreak zone, strengthen zone, and take-up zone provides the necessary ease of feed to the final process speed. These ratio steps result in unique recipes specific to the unique type yarn Y.

  In addition to the operability criteria, the unique hardware safety criteria for each location is stored in the system database. Safety limits such as maximum motor speed are entered as system management functions and their values are stored in the system database. When the calculated roll speed is higher than the system safety limit, the operator is alerted by a different graphic color change of the unique roll icon. Thus, the selected parameters are validated against predetermined safety and operability criteria before being entered into the recipe. The zone ratio or initial speed is then adjusted to achieve a safe roll speed.

  A background monitoring routine resident in the system computer 112 periodically issues data requests to each location device to verify the status of machine operation via the bus network 120. If necessary, a log file may be created by the system computer 112 to record this data. Since the recipe is downloaded to a location using the same bus, monitoring is interrupted during the recipe download to maintain data integrity. Monitoring is resumed when the recipe download is complete.

  Those skilled in the art having the benefit of the teachings of the invention as described above may make modifications and extensions thereof. Such modifications and extensions are to be construed as being within the scope of the invention as defined by the appended claims.

1 is a schematic view of one position in a prior art multi-position stretch-break device. FIG. FIG. 2 is a schematic view of the modification of FIG. 1. FIG. 2 is a detailed block diagram of a computer system and associated controller for executing a program by the method of the present invention to control each position. 3 is an example of a screen display generated by the graphical user interface of the computer system of FIG. It is a table | surface which shows the example of the multistep process recipe by this invention.

Claims (19)

A method for starting or stopping each of at least two separately controllable roll sets used to treat a yarn Y in a stretch-break process, each roll set including at least two rolls And said method is
Each roll set, for each roll set, in accordance with a predetermined sequence and in coordination with at least one speed change of the other roll, so as to minimize simultaneous complete failure of the yarn Y being processed in the stretch-break process Changing the speed of the process from an initial condition to a steady state condition.   The method of claim 1, wherein the speed of each roll is changed to the steady state in at least two separate steps.   The method of claim 1, wherein the speed of each roll is continuously changed to the steady state.   The method of claim 1, wherein the initial condition is a stop condition.   The method of claim 1, wherein each roll set comprises each pair of adjacent rolls in sequential contact with the yarn Y.   The method of claim 1, wherein during the stretch-break process, the yarn Y is annealed and the method further comprises selecting at least one annealing temperature. The stretch-break process includes at least three rolls (26, 34, 56), and the predetermined sequence comprises:
a) selecting candidate speeds for each of the three rolls;
b) checking the validity of the candidate speed for each roll against a predetermined operability criterion;
The method of claim 1, comprising: c) setting a speed for each of the three rolls for a speed that satisfies the operability criteria.   The method of claim 7, wherein each roll set comprises each pair of adjacent rolls in sequential contact with the yarn Y. The stretch-break process comprises at least one jet or reinforcement device (32, 36, 52), the method comprising:
8. The method of claim 7, further comprising selecting at least one operating parameter for the jet.   The method of claim 9, wherein during the stretch-break process, the yarn Y is annealed and the method further comprises selecting at least one annealing temperature.   The method of claim 9, wherein the jet operating parameter comprises an operating pressure, and the operating pressure is selected in at least two separate steps.   12. The method of claim 11, further comprising changing the operating pressure to each of the two pressure steps in coordination with a change in at least one speed of the roll.   The method of claim 9, wherein the jet operating parameter comprises an operating pressure, and the operating pressure is selected as a continuous range of pressures.   14. The method of claim 13, further comprising changing the operating pressure through the range in coordination with a change in at least one speed of the roll.   9. The stretch break process includes a winder operable to collect the yarn on a bobbin under tension, and the method further comprises selecting a tension applied to the yarn by the winder. The method described in 1.   9. The method of claim 8, wherein the candidate operating speed is selected using a graphic display interface, the interface displaying a diagram of the process and having a window for the operating speed entry.   17. Each predetermined usability criterion is compared to each candidate operation speed entry, and the result of the comparison is visually displayed to indicate the speed that meets or exceeds the predetermined usability criterion. the method of.   12. The method of claim 11, wherein the candidate operating pressure is selected using a graphic display interface, the interface displaying a diagram of the process and having a window for entry of the operating pressure. The method of claim 18, wherein each predetermined usability criterion is compared to each candidate operating pressure entry, and the result of the comparison is visually displayed to indicate the pressure that satisfies the predetermined usability criterion.